1. Field of the Invention
This invention concerns cabinet structures and more particularly mounting hardware for reversible refrigerator doors.
2. Background Discussion
It is common practice in the mounting of formed cabinet doors to utilize a socket or bushing element mounted within the interior space of the cabinet door to receive and provide pivotal support for the hinge pins which are secured to the cabinet. This is particularly true in refrigerator cabinetry since the doors are constructed of sheet steel, formed into a door by forming the edges of the outer panel with rearwardly extending flanges comprising the door lateral edges and reentrant flanges to which is secured the inner liner panel of the door.
The interior space so formed is filled with insulating material.
Thus, the door structure consists of a relatively thin gauge sheet metal, not of adequate strength to provide support for the hinge pins by merely forming pin receiving openings in the door edges.
There have been various design approaches which involve mounting hinge pin sockets within the interior of the door, these sockets comprised of sleeves having hinge pin receiving bores. One method is to utilize sockets formed of steel and weld the sockets to the interior surface of the lateral edges, over suitably located clearance openings in the door edge. While a welded joint would normally provide a high strength securement of the socket to the door edge, under production conditions it is not always possible to assure complete reliability of the welds produced such that occasional failures are encountered.
In addition, the welding of the hinge pin socket to the door edge is usually done before surface treatment, i.e., bonderizing, etc. of the formed door. Such surface treatments generally involve aqueous solutions which must be thoroughly drained from the door to insure complete drying prior to painting. The opening in the door edge receiving the hinge pin provides a convenient, adequately sized drain hole if it were possible for the hole to remain clear until after this production stage has been reached. Since the welding process is necessary before such surface treatment, a special drain hole must be cut into the door edge since the solutions tend to be impounded by the flanges. Such opening must then be resealed, hence increasing the manufacturing costs involved.
Another approach which has been utilized involves the swaging of an opening into the door edge, into which is pressed a plastic or steel socket in order to obtain adequate support for the hinge pin. It can be appreciated that the swaged lip about the opening would preclude its use as the drain hole, as does the welding method referred to above.
In addition, it has been the experience with this approach that the sockets have a tendency to be loosened after extensive use since the opening and closing of the door to the full stop position exerts a loosening force on the socket.
Yet another approach has involved the use of a "square hole" engagement with a plastic hinge pin socket in which a specially shaped hole is formed in the door panel and a recess formed in the plastic socket engages the square hole to lock to the lateral edge of the hole. This approach may not provide adequate strength to prevent loosening of the socket since only the thickness of the sheet metal is available to support the socket pin. Another drawback results from the hinge pin socket being provided with tool receiving splines which represent a discontinuity creating a stress point which further contributes to the incidence of failure of these elements. The size and position of the square hole is also critical such that the forming of the door could not take place prior to punching of the hole, and thus, the hole had to be formed after the door was formed, a more difficult manufacturing step. The close tolerance of the square hole itself requires post piercing rather than a simple punch operation.
The strength of the hinge pin socket is important in the design of these units since good design practice dictates that if the door is opened to the full stop position with sufficient force to create a failure, this failure preferably occurs in the door stop rather than in the door panel or hinge construction such that the door may still be opened and closed. Accordingly, the hinge pin socket and mounting which absorbs the hinge pin load should be of relatively high strength. Many of the door mount designs have not been of adequate strength to prevent hinge pin failures, contrary to this desired design goal.
This was due to splitting of the hinge pin sockets under pressure by the hinge pins, particularly a problem where a tool driving recess is located so as to be loaded by the hinge pin when the door stop is engaged as described above.
In connection with the installation of hinge pin sockets, the installation force which may be applied is often fairly limited, particularly since such sockets are advantageously made of molded plastic so as to be low in cost and provide friction-free pivoting of the hinge pins. It is difficult to combine tight secure mounting while keeping installation forces at modest levels within the limits of the strength of available plastic materials.
It is common practice to provide for reversibility of the doors of refrigerator cabinetry. That is, that the door handles and hinge hardware may be positioned from side to side on the door such that the door opening and closing can take place from either side of the refrigerator to adapt the refrigerator to convenient access at different locations. Such reversibility requires mounting hardware for the door handle at each corner since the door handle must be able to be removed and reinstalled at either side of the door. In addition, the lower corners of each door must be provided with the mounting hardware of the door stop. This mounting hardware generally comprises mounting plates or fasteners which are secured and retained within the interior space of the door on the lateral edges such that one can merely remove the screws securing the door handle and door stop to the door and reinstall them at opposite locations.
It would of course be advantageous if the mounting hardware for both the hinge pin sockets and the door handle and door stop could be combined in a single hardware item.
Accordingly, it is an object of the present invention to provide an arrangement for mounting hinge pin sockets within cabinet doors which affords a relatively high strength mounting.
It is another object of the present invention to provide an arrangement for mounting the hinge pin socket which does not require a welding operation and which leaves the hinge pin socket clearance opening clear in the door edges such that it may be utilized as a drain hole for surface treatment liquids prior to installation of the hinge pin sockets.
It is yet another object of the present invention to provide such a mounting arrangement in which the socket is securely retained without any tendency to become loosened but which may be installed with the application of relatively modest forces, such that molded plastic sockets may be utilized.
It is still a further object of the present invention to provide an arrangement utilizing a single hardware item to which is mounted the door handle, door stop and hinge pin sockets.
It is another object of the present invention to provide a mounting arrangement for articles such as the hinge pin sockets for securing such articles with a relatively low driving force while creating a nonloosening secure mount.